Reversible ratchet mechanism



Jan. 29, 1952 BURDICK 2,583,544

REVERSIBLE RATCHET MECHANISM Filed May 19, 1945 l N VE N TOR.

CLIFFORD I. BURDICK 7 nrromvs Patented Jan. 29, 1952 REVERSIBLE RATGHET MECHANISM Clifford I. Burdick, Racine, Wis., assignor to Snap-On Tools Corporation, Kenosha, Wis., a

corporation of Delaware Application May 19, 1945, Serial No. 594,699

Claims.

This invention relates to ratchet devices and more particularly to improved ratchet wrench construction for increasing the durability and service longevity thereof, although certain features thereof may be employed with equal advantage for other purposes.

It contemplates more especially the provision of an improved ratchet device construction which embodies improved friction ratchet ele-. ments that insure more dependability, durability, less wear, greater ratcheting flexibility, and extended service for devices of this character or type.

Friction ratchet wrenches of numerous types have heretofore been proposed and they embody substantially the same general elements that are subjected to excessive wear, impacts and are called upon to sustain heavy turning loads so that replacement is often found necessary. Further, in view of these unusual heavy requirements imposed upon ratchet wrenches, they are subjected to exceedingly heavy service and must soon be replaced in that the moving parts soon become worn or broken. Friction ratchets are fundamentally capable of sustaining greater loads and are subject to less wear, but have not proven too dependable in their ratcheting action.

One object of the present invention is to simplify the construction and improve the operation of devices of the character mentioned.

Another object is to provide an improved friction ratchet wrench construction which is more durable and dependable in operation.

Still another object is to provide a friction ratchet wrench construction that is more simple, durable, and less expensive from a service standpoint.

A further object is the provision of improved reversible and position control means for the pawl gripper parts of a ratchet wrench that sustains the greatest load and affords extended service without any appreciable wear thereon.

A still further object is to provide ratchet wrench with improved friction rollers and controls therefor that will sustain excessive loads for extended periods and insure dependable reversible ratcheting action.

Still a further object is to provide improved friction roller devices as improved pawl elements comprising important parts of the ratchet wrench construction.

Other objects and advantages will appear from the following description of an illustrative embodiment of the present invention.

In the drawing:

Figure 1 is a plan view of a device embodying features of the present invention.

Figure 2 is a fragmentary side view in elevation of the head portion of the wrench shown in Figure 1.

Figure 3 is a fragmentary view corresponding with Figure 1 having the cover plate removed to clarify the showing. I

Figure 4 is a sectional view taken substantially along line IV-IV of Figure 1.

Figure 5 is a fragmentary sectional view taken substantially along broken line V-V of Figure 2.

Figure 6 is a side view in elevation of a friction pawl roller shown assembled in Figures 3 and 5.

Figure 7 is a side view in elevation of the pawl roller cage positioning lever and control.

The structure selected for illustration comprises a cast, forged or otherwise shaped body In which is suitably recessed to define a circular chamber II open on both sides for the reception of a revoluble member I2. The body I0 has an elongated handle III of any suitable shape formed integral therewith or otherwise attached thereto. The revoluble member I2 is retained for journaled rotation within the chamber II of the body Ill by means of confronting face plates I3 and II which conform in contour with the recessed openings I5-I6 communicating with the chamber II. The cover plate I3 is sized for press-fitted attachment to the body It while the cover plate I4 is detachably associated with the recessed body opening I6 for retention by means of suitable fasteners IT. The

fasteners I! in this instance two, extend through the face plate I4 for engagement with the body Ill. The circular chamber II and the confronting face plate I3 provide axially aligned bores I8 and I9, respectively, to rotatively support the revoluble member I2 having axially extending hubs 20 and 2i The hub 2I is appreciably smaller than the circular hub 20 of the revoluble member I2, and the former terminate in a polygonal shank 22, in this instance; square cross-section, sockets for various nut sizes thereon.

In order to impart intermittent rotation to the revoluble member I2 responsive to oscillatory movement of the handle ID, the periphery of the hub 20 confronts friction rollers, in this instance two circumferentially spaced sets 23-24, each set 23 and 24 comprising two spaced friction rollers mounted on pins 25-26, respectively. The pins 25-26 preferably though not essentially are formed integral with the rollers 23-24 by providing annular grooves 23-24 therein alonga to detachably receive 3! of the cradle plate 28 (Figure 5) is described from the same axis by a larger radius than the inner curved edge 29 to aiford the circumferential oscillatory displacement thereof in an elon- V gated arcuate transverse ratcheting chamber 32 provided in the body iii to communicate with the circular chamber H which confines the revoluble member l2.

The elongated 'arcuate ratcheting chamber 32 accommodates the friction rollers 23-44 and theirshifting cradle 21 as will appear more fully hereinafter. The friction roller annular grooves 23-24' and their communicating pins Zia- 26 are complements of semi-circular transverse grooves '-26 provided proximate to the extremities of the arcuate cradle 21. The transverse semi-circular grooves 25-25' communicate with the outer arcuate edge 3| thereof, thereby retaining the cradle 2? within the angular grooves 2324' of the friction roller 23- 2 3, respectively. The friction rollers 23-24contact the} lower camming edges 33-34 which are also circumscribed along an are so as todefine the elongatedarcuate ratcheting chamber 32 with a depthiin itscentralregion commensurate with I the diameter-of the rollers 23-44 to effect frictionalengagement between the revoluble member l 2 and the head member IE through the rollers' 23'-24. 'These friction engaging positions between the rollers 23-2 3 and the camming edges 33- 3d, respectively, are proximate to the central-region of-the -ratcheting chamber 32 which communicates at its center with a circular recess 35 which will be presently described. It should be noted that the elongated ratcheting chamber 32- hasitsgreatest depthat its curved ends 3-5.3'l so that the friction rollers 23-2 i will be free from engagement with the revoluble member hub'20 and the camming surfaces 33-34 of the head member ie when one or the other of the friction rollers 23-24 are shifted toward the ratcheting chamber enlarged ends 36 or 31. Consequently, the position of thee radle21 within the ratcheting chamber 32 will determine whether or'not" the; rollers 23 or 24 are engaged or wedged between the revoluble member hub 20 and the cammingsurfaces 33-01 34 of the head member 16.

The circular recess -35 confines a cylindrical cradle positioningtrunnion 38 (Figure 7) which is milled or otherwise shaped to provide a radially extending tooth t9--having converging side surfaces 40-4l"t0 cooperate with a spring impelled detent'42. Thespring impelled detent 42 consists, in this-instance, of a spherical ball which isconfined in a longitudinally extending bore 43 having aspring 44 disposed therein below the spherical detent Q2. The spherical detent 42 is urged in the direction of the trunnion tooth 39 Vfor'engagement with one or the other of the converging-surfaces ill-4i to maintain the trunnion 38 in one or the other of two operable angular positions.

The trunnion 38- controls the position of the friction roller cradle 21 through the median of-a the camming surfaces 33 or 24. determinesthegdirection of friction roller ratchsubstantially U-shaped trip member 45 that is embodied in the cylindrical surfaces of the trunnion 38 diametrically opposite the tooth 38 therein. The U-shaped trip member projects from the trunnion 38 to register with a slot 46 provided in the friction roller cradle 2'! to communicate with the outer arcuate edge 3! thereof. The radial position of the trunnion 38 determined by the surface 40 or M of the tooth 39 that is engaged by the spring impelled detent 42, will control the position of the friction roller cradle 27 and the respective rollers 23 or 26.

The position of the'friction roller cradle 21 determines which rollers 23 or 24 are frictionally wedged between the revoluble member 12 and This, in turn,

eting of the revoluble member I2 responsive to oscillatory movement manually imparted to the handle H). In order to radially shift the positioning-trunnion'fifi and thus control the directionof ratcheting which is determined by the position of the friction roller cradle 2l,'an externally accessible finger manipulating lever; 41 is fixed to the trunnion 38. To this end, the lever 47 has one end 48 thereof of reduced depth formounting in azslot provided diametrically through theend 5B of the trunnion 38. This reduced lever-end 48 is fixedly attached to the trunnion '38 vto impart the desired rotary movement thereto. :Consequently, lthe direction ofratchet= ing can-be controlled with the finger manipulat 7 ing lever 4'! as will appear more fully hereinafter, It should be noted that the body It is inwardly offset'as' at-5l (Figure 2) in the intermediate shank region 52 to accommodate the trunnion positioning lever 41 so thatthe inwardly offset reducedend 48 thereof will project beneath the face plate M and the top edge of the lever will be in the plane thereof (Figure 2). The con fronting faceplate; i3il extend over the circular recess'35 to confine the trunnion 38 in the bore 35, thereby maintaining the revoluble mem ber l2 and all of its ratcheting control elements assembled within the body it. 2

With the arrangement of parts above described, anysuitable device for turning such as wrench sockets: (not shown) may be detachably or otherwise associated with the revoluble member 12,

being preferably though not essentially provided witha spring impelled detent 22' of standard construction so that wrench sockets having vari- Qu-sly: sized openings or other fastener turning accessories-.-may' be detachably associated there with. The manual trunnion adjusting lever M may-be provided for adjustment relative to suitable indicia; in this instance, directional on and "off* indicators 53 and 54 inscribed on theexternal faceof the body It.

Displacement of the friction roller cradle 21 in a-counter-clockwise direction (viewed from Figure-3 occasioned by displacing the lever 41 to -on-position, will cause the friction rollers 23 to engage the periphery 2t and the camming surface 33 for wedged insertion therebetween for urging the revoluble member I2 in a corresponding direction to tighten or engage a right hand threaded member. While the cradle 21 is in this position, the friction rollers 24 are positioned in the enlarged end region 3'! of the ratcheting chamber 32 where they are free from engagement and thus inoperative;

Opposite lever displacement indicated bydibe turned on and o and the extent of each bite or intermittent rotation of the revoluble member 12 will depend upon the ratcheting stroke which is within the control of the attendant.

While I have illustrated and described a preferred embodiment of this invention, it must be understood that the invention is capable of considerable variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

I claim:

1. In a ratchet mechanism, the combination with a body member, of a revoluble member journalled in said body member, said members com prising intermittent driving and driven elements, there being an elongated arcuate chamber in said body member communicating with said revoluble member to present integral camming surfaces toward and from said revoluble member, elongated. arcuate carrier means mounted for displacement within said body member camming chamber, said camming chamber and carrier extending for a circumferential portion of said revoluble member,

friction rollers rotatively mounted in the extremities of said carriermeans for circular displacement therewith in opposite directions to engage and disengage said revoluble member, the camming surfaces of said elongated chamber termimating in enlarged ends for receiving said friction rollers when said carrier is shifted to one extreme position or another to disengage the friction rollers displaced thereto and engage the friction rollers'displaced therefrom, means assoi ciated with said friction carrier means for shifting said friction rollers along said camming chamber in operative and inoperative engaging relation with said revoluble member, and means operatively connected with said shifting means to ,3,

maintain the latter in one or the other of its extreme displaceable positions 2. In a ratchet mechanism, the combination with a body member, of a revoluble member journalled in said body member, said members comprising intermittent driving and driven elements, there being an elongated arcuate chamber in said body member communicating with said revoluble member to present integral camming surfaces toward and from said revoluble member, elonated arcuate carrier means mounted for displacement within said body member camming chamber, said camming chamber and carrier extending for a circumferential portion of said revoluble member, friction rollers ro-tatively mounted in the extremities of said carrier means for circular displacement therewith in opposite directions to engage and disengage said revoluble member, the camming surfaces of said elongated chamber terminating in enlarged ends for receiving said friction rollers when said carrier is shifted to one extreme position or another to disengage the friction rollers displaced thereto and engage the friction rollers displaced therefrom, means associated with said friction carrier means for shifting said friction rollers along said camming chamber in operative and inoperative engaging relation with said revoluble member, and friction means operatively associated with said shifting means to maintain the latter in one or the other of its extreme displaceable positions.

3. In a ratchet mechanism, the combination with a body member, of a revoluble member journa1led in said body member, said members comprising intermittent driving and driven elements, there being an elongated arcuate chamber in said body member communicating with said revoluble member to present integral camming surfaces toward and from said revoluble member, e1on gated arcuate carrier means mounted for displacement Within said body member camming chamber, said camming chamber and carrier extending for a circumferential portion of said revoluble member, friction rollers rotatively mounted in the extremities of said carrier means for circular displacement therewith in opposite directions to engage and disengage said revoluble member, the camming surfaces of said elongated chamber terminating in enlarged ends for receiving said friction rollers when said carrier is shifted to one extreme position or another to disengage the friction rollers displaced thereto and engage the friction rollers displaced therefrom, means associated with said friction carrier means for shifting said friction rollers along said camming chamber in operative and inoperative engaging relation with said revoluble member, a trunnion fixed to said shifting means to effect the pivotal mounting thereof in said body member, and means for maintaining said trunnion in extreme opposite pivotal positions to control the direction of ratcheting said revoluble member.

4. In a ratchet mechanism, the combination with a body member, of a revoluble member journalled in said body member, said members comprising intermittent driving and driven elements, there being an elongated arcuate chamber in said body member communicating with said revoluble member to present integral camming surfaces toward and from said revoluble member, elongated arcuate carrier means mounted for displacement within said body member camming chamber, said camming chamber and carrier ex tending for a circumferential portion of said revoluble member, friction rollers rotatively mounted in the extremities of said carrier means for circular displacement therewith in opposite directions to engage and disengage said revoluble member, the camming surfaces of said elongated chamber terminating in enlarged ends for receiving said friction rollers when said carrier is shifted to one extreme position or another to disengage the friction rollers displaced thereto and engage the friction rollers displaced therefrom, means associated with said friction carrier means for shifting said friction rollers along said camming chamber in operative and inoperative en gaging relation with said revoluble member,

' a trunnion fixed to said shifting means to effect the pivotal mounting thereof in said body member, rotary position indexing means provided on said trunnion, and spring impelled means in said body member for cooperating with said trunnion indexing means to maintain said friction rollers in one or the other of their extreme displaceable positions.

5. In a ratchet mechanism, the combination with a body member, of a revoluble member journalled in said body member, said members comprising intermittent driving and driven elements,

7 7 a 7 ther eineaehamb e-in said'b dy-m m' ex communieati;r 1 g-witl saidv revoluble memberto pre sent integral camming'surfaees toward and. from said revoluble member,--carrie r means mounted f r cir ul r displacement in oppos te d r swithin said body memberoamming chamber, and friction rollers rotatively mounted in said carrier means for displacement; therewith in opposite directions to engage and disengage said revoluble member, said carrier meansbeing of lesser length than-and shaped to conform with said camming chamber for movable association with said friction carrier means for shifting said friction rollers along said cam ming chamber in operative and inoperative engaging relation with said 15 2,253,168

revoluble member. 7 CLIFFORD I. BURDICK.

nnsenenoesmmn The following references are of: 'recordiin "the file iofthis patent:

T TE PAT TS Numb r Nam Date 564,250 Knowlton July 21,1896 587,146 Evans July 27, 1897 745,281 Hume, Nov. 24, 1903 892,408 Custer -2--- July 7, 1908 1,372,868 Derby Mar. 29, 1921 1,888,885 vPepperdine ,Nov. 22, 1932 2,110,099 Thewes 'Mar.-1, 1938 2,139,650 Anderson Dec. 13, 1938 Bur-bridge "1. Aug. 19, 1941 

